1. Technical Field
The present inventive concept relates to a random number generator.
2. Discussion of the Related Art
With the development of information and communication technology, information coding and decoding techniques are used to keep information secure. A random number is used, for example, as a secret key of a security system. Therefore, a random number generator may be provided in a system for which security is required. In such a system, the random numbers should not have periodicity and regularity. In other words, the generated random numbers should be unpredictable and non-periodic.
A true random number (TRN), which is generated from a physical noise source, is unpredictable and does not have any periodicity. To generate a TRN, a thermal noise or a shot noise is used as a noise source in a random number generator. Alternatively, a clock signal having an irregular period is generated by a ring oscillator for use as the noise source. Meta-stability has good stochastic properties, and thus meta-stability is used in a true random number generator (TRNG). A latch or a flip-flop is typically used to achieve a meta-stabile state.